Problem: Simplify the following expression: ${-7(-12+10r)-2(-3r-3)}$
Answer: Distribute the ${-7}$ into the first set of parentheses: $ {-7(}\gray{-12+10r}{)} - 2(-3r-3) $ $ {84-70r} - 2(-3r-3) $ Distribute the ${-2}$ into the parentheses: $ 84-70r {-2(}\gray{-3r-3}{)} $ $ 84-70r + {6r+6} $ Rewrite the expression to group the ${r}$ terms and numeric terms: $ {-70r + 6r} + {84 + 6}$ Combine the ${r}$ terms: $ {-64r} + {84 + 6}$ Combine the numeric terms: $ {-64r} + {90}$ The simplified expression is $-64r+90$